textproduct: Albany

WHAT HAS CHANGED

As of 7:30 PM EST...Current radar imagery shows a line of showers across the southern ADKs and Mohawk Valley, tracking eastwards. This line of showers has weakened over the last hour or two. However, 00z KALY sounding and SPC mesoanalysis indicate some modest elevated instability associated with steep mid- level lapse rates above the inversion. So, a few rumbles of thunder remain possible as this line of showers tracks through the region over the next few hours. Still not expecting any severe weather with a very strong low-level inversion in place as seen on the 00z KALY sounding. In fact, with this strong inversion and stubborn low-level cold wedge, temperatures outside of the ADKs and higher elevations of the Catskills are running as much as 5-10 degrees below the previous forecast, so we lowered temperatures through the next several hours. Aside from these temperatures changes, previous forecast remains on track with more details in the previous discussion below...

Previous...Temps continue to trend above normal for much of the upcoming week. The warm temperatures will result in snow melt, and some additional rainfall towards the middle of the week will continue to result in a threat for hydro concerns.

KEY MESSAGES

1) A frontal boundary will allow for a slight chance for thunderstorms tonight, although severe storms are not expected at this time.

2) An extended period of above normal temperatures continues to be expected early to mid week for the entire forecast area. The anomalous warmth, along with some rainfall during the middle of the week, will aid in snow melt, potential river rises, and a subsequent threat of ice jams and minor flooding.

DISCUSSION

KEY MESSAGE 1...

A cold front is located over the Midwest, associated with an area of low pressure across the Great Lakes. Meanwhile, a stalled out warm front extends eastward out of this storm system. While parts western and central New York have seen the boundary move through, the stalled out boundary then turns southward towards the mid Atlantic States, keeping our area within a cooler and more stable air mass. Surface observations and satellite imagery continue to show widespread low clouds across much of the area, although some clearing has occurred for high terrain areas. The 12z KALY sounding shows a very stable layer near the surface thanks to a strong inversion, but there is drier and less stable air above this layer.

The warm front will remain stalled out just southwest of the area for the rest today and into this evening. As the cold front gets closer, both boundaries will be crossing from west to east overnight. Temperatures, currently mainly in the upper 30s to mid 40s, will hold steady through the rest of the day and will slowly rise overnight. Some breaks in the clouds are possible through the rest of today, mainly for high terrain areas, but with the warm front staying to the southwest, it will likely remain fairly cloudy for most valley areas through this evening. The exception may be the Schoharie Valley, which is closer to the warm front and has already seen some clearing trying to move in.

As the boundaries move through tonight, there will be the potential for showers and isolated thunderstorms. There may be initial batch around midnight, with another line for the late night hours. Activity looks scattered, but all areas have the potential for some precip tonight. With the stable air near the surface and the front crossing during the overnight, surface- based instability will be very limited. Still, there could be a rumble or two of thunder, as 3km HRRR suggests elevated instability will still allow for some thunder potential across the area, especially northern and western areas. No severe storms are anticipated, though, as thunderstorms will be weakening and the stable layer near the surface will keep any strong winds from reaching the surface.

Total rainfall overnight will generally be a tenth or two, with perhaps some locally higher totals in the Adirondacks. The rainfall, and some snowmelt from the above-freezing temps, will lead to some runoff, but it won't be enough for any hydro concerns just yet.

KEY MESSAGE 2...

Despite being behind a cold front, a warming trend is expected for Sunday and into the upcoming week. Warming temps aloft and rising heights, combined with a west-southwest flow aloft, should allows above normal temperatures through much of the week. Valley areas will see temps steadily climb each day. After 50s on Sunday, many spots will be in the 60s on Monday, and mid 60s to low 70s by Tuesday. There should be a decent amount of sun each day as well. Overnight lows will fall back into the 30s on Sunday night and Monday night, although milder temps are expected on Tuesday night ahead of the next storm system.

With the warming temps and sunshine, there should be snow melt each day, although it may slow for the overnight hours. The snowpack temperature will be ripening with the warm temps, even in the high terrain areas and snow depth will quickly be compressed and reduced each day. River ice will begin to rot in place, although if enough runoff occurs, there could be some ice breaking up and movement as well.

The potential for hydro related issues could increase towards the mid-week, as another storm system will have the potential to bring some rain showers. Models still vary on the exact timing, but some rain will a warm front is possible by Tuesday night or Wednesday, with some showers along the cold front by later Wednesday into Thursday. If enough rainfall occurs, this could allow for ice jam concerns due to the movement of river ice. Even outside the rivers, some minor flooding could occur from the rain and snowmelt, especially in urban and low lying areas. There still remains uncertainty regarding exact QPF, as this will determine just how much runoff occurs. The latest MMEFS shows some potential for issues along the Housatonic River and perhaps across the Adirondacks as well.

Behind this system, some colder air will return, which could even allow for some precip to end as snow, mainly for northern and high terrain areas. Temps will be cooler for the late week, but nothing that will be out of ordinary for mid March.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

Through 00z Monday...Conditions have trended down to IFR (cigs) at ALB/POU/PSF and low-end MVFR at GFL. Mainly IFR/MVFR cigs and VFR to MVFR vsbys through the first couple hours of the TAF period. Then, a weakening line of showers tracks through the region. A few rumbles of thunder can't be ruled out, but confidence remains too low to include in the TAFs. With these showers, continued MVFR/IFR cigs and MVFR to briefly IFR vsbys possible. Showers diminish in coverage 06- 08z, but low confidence on how long IFR cigs will linger into tonight. Highest confidence is at POU/PSF, but will still mention SCT clouds below 1000 ft at ALB/GFL through early tomorrow morning. Then, as a cold frontal boundary moves through the region, low-level moisture mixes out with a trend back to MVFR and eventually VFR vsbys and cigs by mid to late morning through the end of the TAF period.

Winds tonight will be at 5-10 kt from the SE, veering to the SW after 06z at ALB/GFL, and at around 5 kt or less at POU/PSF. Will also mention LLWS at all terminals tonight with the low-level jet veering from the SW to W/SW at 40-60 kt. Tomorrow, winds shift to the west at around 10 kt with gusts to around 20 kt at all terminals by mid to late morning, lasting through the end of the TAF period.

Outlook...

Sunday Night through Tuesday: No Operational Impact. NO SIG WX. Tuesday Night: Low Operational Impact. Slight Chance of RA. Wednesday: High Operational Impact. Likely RA. Wednesday Night: High Operational Impact. Breezy. Likely RA. Thursday: High Operational Impact. Breezy. Likely RA...SN.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.